Re: kgdb: allow static kgdbts boot configuration

Re: kgdb: allow static kgdbts boot configuration

[Andrew Morton]

On Fri, 18 Apr 2008 19:00:57 GMT
Linux Kernel Mailing List <linux-kernel@vger.kernel.org> wrote:

> Gitweb:     http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=974460c5bfd9f6c38aa3dda189a63f9fc351035f
> Commit:     974460c5bfd9f6c38aa3dda189a63f9fc351035f
> Parent:     e3e2aaf7dc0d82a055e084cfd48b9257c0c66b68
> Author:     Jason Wessel <jason.wessel@windriver.com>
> AuthorDate: Thu Mar 20 13:43:44 2008 -0500
> Committer:  Ingo Molnar <mingo@elte.hu>
> CommitDate: Thu Apr 17 20:05:43 2008 +0200
> 
>     kgdb: allow static kgdbts boot configuration
>     
>     This patch adds in the ability to compile the kgdb internal test
>     string into the kernel so as to run the tests at boot without changing
>     the kernel boot arguments.  This patch also changes all the error
>     paths to invoke WARN_ON(1) which will emit the line number of the file
>     and dump the kernel stack when an error occurs.
>     
>     You can disable the tests in a kernel that is built this way
>     using "kgdbts="
>
> ...
>
> +#ifdef CONFIG_KGDB_TESTS_BOOT_STRING
> +static char config[MAX_CONFIG_LEN] = CONFIG_KGDB_TESTS_BOOT_STRING;
> +#else
>  static char config[MAX_CONFIG_LEN];
> +#endif

I expect that CONFIG_KGDB_TESTS_BOOT_STRING is always defined here.  Or if
not, that it is possible to arrange for that with sufficient Kconfig
cleverness.  If so, the ifdef shouldn't be needed.

> +config KGDB_TESTS_ON_BOOT
> +	bool "KGDB: Run tests on boot"
> +	depends on KGDB_TESTS
> +	default n
> +	help
> +	  Run the kgdb tests on boot up automatically without the need
> +	  to pass in a kernel parameter
> +
> +config KGDB_TESTS_BOOT_STRING
> +	string "KGDB: which internal kgdb tests to run"
> +	depends on KGDB_TESTS_ON_BOOT
> +	default "V1F100"
> +	help
> +	  This is the command string to send the kgdb test suite on
> +	  boot.  See the drivers/misc/kgdbts.c for detailed
> +	  information about other strings you could use beyond the
> +	  default of V1F100.

I dunno.  Do we *really* need this feature?  I mean, if you want to run the
tests, you provide the boot parameter and that's it.  Adding this
Kconfig-time stuff on top seems excessive.

Re: kgdb: allow static kgdbts boot configuration

[Ingo Molnar]

* Andrew Morton <akpm@linux-foundation.org> wrote:

> > +config KGDB_TESTS_ON_BOOT
> > +	bool "KGDB: Run tests on boot"
> > +	depends on KGDB_TESTS
> > +	default n
> > +	help
> > +	  Run the kgdb tests on boot up automatically without the need
> > +	  to pass in a kernel parameter
> > +
> > +config KGDB_TESTS_BOOT_STRING
> > +	string "KGDB: which internal kgdb tests to run"
> > +	depends on KGDB_TESTS_ON_BOOT
> > +	default "V1F100"
> > +	help
> > +	  This is the command string to send the kgdb test suite on
> > +	  boot.  See the drivers/misc/kgdbts.c for detailed
> > +	  information about other strings you could use beyond the
> > +	  default of V1F100.
> 
> I dunno.  Do we *really* need this feature?  I mean, if you want to 
> run the tests, you provide the boot parameter and that's it.  Adding 
> this Kconfig-time stuff on top seems excessive.

yes, i believe we really need this - this is what caught the recent 
regression in kgdb. It should all be default-off.

	Ingo